Interest in the separation and recovery of carbon dioxide from hydrocarbon gas streams containing a large percentage of carbon dioxide comes primarily from recovery of carbon dioxide from gas streams associated with enhanced oil recovery (EOR) projects employing carbon dioxide for miscible flood of oil reservoirs, thereby allowing the recovered carbon dioxide to be reinjected into the oil reservoir.
Several commercial processes i.e. Selexol, Benfield, Catacarb, Ryan/Holmes, etc. are claimed to be suitable for bulk CO.sub.2 recovery from hydrocarbon streams. Complications arise in these processes, however, because of solvent contamination with C.sub.2 and heavier hydrocarbon components which are present in miscible flood gas, and which cause foaming in the solvent of the absorption system in these processes. Consequently with each of above mentioned commercial processes, there is a disadvantage in processing gas produced from a typical oil reservoir flood which can result in adverse economic factors such as excessive operating cost, royalty payments, initial plant investment, solvent toxicity, etc., that render the process uneconomical for processing miscible flood gas.
Accordingly it is an object of this invention to provide a process for bulk recovery of CO.sub.2 from a gaseous mixture.
It is a further object of this invention to provide a process for economically recovering CO.sub.2 from normally gaseous mixtures comprising hydrocarbons and CO.sub.2.
It is a still further object of this invention to recover a CO.sub.2 stream from an EOR project which is substantially free of hydrocarbons so as to be suitable for reinjection into an oil well.